CN103075114B - A kind of box cupling - Google Patents
A kind of box cupling Download PDFInfo
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- CN103075114B CN103075114B CN201310017792.9A CN201310017792A CN103075114B CN 103075114 B CN103075114 B CN 103075114B CN 201310017792 A CN201310017792 A CN 201310017792A CN 103075114 B CN103075114 B CN 103075114B
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- internal thread
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Abstract
The invention discloses a kind of box cupling, for coal-bed gas exploitation, internal thread is provided with in described box cupling, the pitch size of described internal thread is identical, the tooth top circular arc radius size of described internal thread is different, at the bottom of the tooth of described internal thread, arc radius varies in size, and at the bottom of described tooth top arc radius and described tooth, arc radius is all in the scope of 0.43mm-0.51mm.The present invention is on the basis of API threaded collar joint, the pitch size of internal thread is constant, at the bottom of internal threads tooth top and tooth, arc radius makes change, make the size of the arc radius at the bottom of tooth top and tooth different in the scope of 0.43mm-0.51mm, during internal and external threads engagement, compared to existing technology, reduce the difference of arc radius at the bottom of the tooth top arc radius of internal and external threads and tooth, the gap existed after reducing internal and external threads engagement, significantly promote the water-stop ability after internal and external threads engagement, increase the torque resistant ability of screw thread, enhance the security reliability of the tubing string that is threaded, in addition, the present invention is easy to processing, and structure is simple, the lower but Be very effective of cost.
Description
Technical field
The present invention relates to coal-bed gas exploitation field, particularly a kind of box cupling.
Background technology
Coal bed gas, is commonly called as gas, be compose exist in coal seam with methane be main component, based on be adsorbed on matrix of coal particle surface, part be free in coal hole or the hydrocarbon gas be dissolved in coal seam water, be a kind of novel clean energy and high-quality industrial chemicals.Coal bed gas is generally positioned at the degree of depth of underground about 500m, coalbed methane reservoir has the feature of low pressure, hypotonic and low yield, generally by fracturing mode, coal bed gas is exploited, the tubing amount needed during exploitation is larger, require that the screw thread of exploitation tubing string must meet certain water-stop ability, also will control its cost of manufacture as far as possible.
At present, coal-bed gas exploitation tubing string screw thread uses API(AmericanPetroleumInstitute, American Petroleum Institute (API)) standard round screw thread, arc radius at the bottom of the tooth of this screw thread and tooth top arc radius are all evenly constant, and arc radius at the bottom of tooth is 0.43mm, and tooth top arc radius is 0.51mm, the larger spirality channel in gap is there is during the screw-threaded engagement of this dimensional parameters, in addition, tubing string lower fashionable frictional resistance in horizontal well is comparatively large, and tubing string will bear larger moment of torsion.
Realizing in process of the present invention, inventor finds that prior art at least exists following problem:
In prior art screw thread tooth at the bottom of arc radius and tooth top arc radius all evenly constant, and arc radius difference at the bottom of tooth top and tooth is larger, so there is the larger spirality channel in gap after internal and external threads engagement, when Hydraulic fracturing pressure is larger, screw-threaded engagement place easily leaks, and when bearing larger torque load in horizontal well, nipple easily damages, this makes the use of API standard round screw thread be subject to a definite limitation.
Summary of the invention
Causing more greatly easily occurring the problem of leakage and nipple torque resistant ability in order to solve gap, prior art screw-threaded engagement place, embodiments providing a kind of box cupling.Described technical scheme is as follows:
A kind of box cupling, for coal-bed gas exploitation, internal thread is provided with in described box cupling, the pitch size of described internal thread is identical, the tooth top circular arc radius size of described internal thread is different, at the bottom of the tooth of described internal thread, arc radius varies in size, and at the bottom of described tooth top arc radius and described tooth, arc radius is all in the scope of 0.43mm-0.51mm.
Concrete, as preferably, the middle part from the end of described internal thread to described internal thread, the tooth top arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm.
Concrete, as preferably, the hand-tight position from the end of described internal thread to described internal thread, the tooth top arc radius of described internal thread is 0.51mm; Power-tight position from the hand-tight position of described internal thread to described internal thread, the tooth top arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm; Middle part from the power-tight position of described internal thread to described internal thread, the tooth top arc radius of described internal thread is 0.43mm.
As preferably, the middle part from the end of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, arc radius linearly increases to 0.51mm by 0.43mm.
As preferably, the hand-tight position from the end of described internal thread to described internal thread, arc radius at the bottom of the tooth of described internal thread is 0.43mm; Power-tight position from the hand-tight position of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, arc radius linearly increases to 0.51mm by 0.43mm; Middle part from the power-tight position of described internal thread to described internal thread, arc radius at the bottom of the tooth of described internal thread is 0.51mm.
The beneficial effect that the technical scheme that the embodiment of the present invention provides is brought is:
The embodiment of the present invention is on the basis of API threaded collar joint, the pitch size of internal thread is constant, internal threads tooth top and the arc radius at the bottom of tooth make change, make the size of the arc radius at the bottom of tooth top and tooth different in the scope of 0.43mm-0.51mm, during internal and external threads engagement, compared to existing technology, reduce the difference of arc radius at the bottom of the tooth top arc radius of internal and external threads and tooth, the gap existed after reducing internal and external threads engagement, significantly promote the water-stop ability after internal and external threads engagement, increase the torque resistant ability of screw thread, enhance the security reliability of the tubing string that is threaded, in addition, the present invention is easy to processing, and structure is simple, the lower but Be very effective of cost.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the structural representation of the box cupling that the embodiment of the present invention provides.
Wherein: 1 tooth top, at the bottom of 2 teeth, 3 ends, 4 hand-tight positions, 5 power-tight positions, in the middle part of in the of 6.
Detailed description of the invention
For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.
As shown in Figure 1, embodiments provide a kind of box cupling, for coal-bed gas exploitation, internal thread is provided with in described box cupling, the pitch size of described internal thread is identical, tooth top 1 arc radius of described internal thread varies in size, and at the bottom of the tooth of described internal thread, 2 arc radius vary in size, and at the bottom of described tooth top 1 arc radius and described tooth, 2 arc radius are all in the scope of 0.43mm-0.51mm.
Wherein, each pitch size in internal thread is identical, and all identical and constant with API threaded collar joint internal thread pitch, pitch is transverse tooth thickness and space width sum, in the embodiment of the present invention, pitch is identical, certainly, those skilled in the art are known, and pitch is identical can be that the transverse tooth thickness of internal thread is all identical with space width constant, thus make pitch constant, also can be that transverse tooth thickness and the space width of internal thread all changes, but final transverse tooth thickness and space width sum constant, namely pitch is constant.
The embodiment of the present invention is in order to reduce costs as much as possible, and improve the general applicability of box cupling, on the basis of API threaded collar joint, the pitch size of internal thread is identical and constant, at the bottom of internal threads tooth top 1 arc radius and tooth, 2 arc radius make change, make the size of 2 arc radius at the bottom of tooth top 1 arc radius and tooth different in the scope of 0.43mm-0.51mm, due in prior art, all tooth top arc radius are 0.51mm, and arc radius at the bottom of tooth is 0.43mm, and the embodiment of the present invention makes all tooth top 1 arc radius all change into is less than or equal to 0.51mm, 2 arc radius at the bottom of all teeth are all changed into and is more than or equal to 0.43mm, on the whole, when internal and external threads engages, reduce the total difference of 2 arc radius at the bottom of internal and external threads tooth top 1 arc radius and tooth, external screw thread refers to the external screw thread on the sleeve pipe or tubing string that are threaded with box cupling, external screw thread is used for and coupling inner thread engagement, the overall gap existed after reducing internal and external threads engagement, significantly promote the water-stop ability after internal and external threads engagement, torque resistant ability after internal and external threads engagement simultaneously increases, strengthen the security reliability of the tubing string that is threaded, in addition, the present invention is easy to processing, and structure is simple, the lower but Be very effective of cost.
As shown in Figure 1, concrete, as preferably, the middle part 6 from the end 3 of described internal thread to described internal thread, tooth top 1 arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm.
Concrete, as preferably, the hand-tight position 4 from the end 3 of described internal thread to described internal thread, tooth top 1 arc radius of described internal thread is 0.51mm; Power-tight position 5 from the hand-tight position 4 of described internal thread to described internal thread, tooth top 1 arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm; Middle part 6 from the power-tight position 5 of described internal thread to described internal thread, tooth top 1 arc radius of described internal thread is 0.43mm.
Wherein, when hand-tight position 4 refers to that the internal and external threads engagement magnitude of interference is zero, the position of external thread sleeve pipe end; After power-tight position 5 refers to and carries out fastening upper button by preset torque machine, the position that external thread sleeve pipe end reaches; The internal thread of box cupling both sides is about 6 symmetries in the middle part of it, be more than two kinds of preferred tooth top 1 arc radius change programmes, certainly, those skilled in the art are known, also can there is other change programme, if the end 3 from internal thread is to hand-tight position 4, tooth top 1 arc radius is linearly reduced to 0.43mm by 0.51mm, or, from the end 3 of internal thread to power-tight position 5, tooth top 1 arc radius is linearly reduced to 0.43mm etc. by 0.51mm, as long as make tooth top 1 arc radius of internal thread have the change of reduction, thus the overall gap existed after internal and external threads is engaged reduces.
As shown in Figure 1, concrete, as preferably, the middle part 6 from the end 3 of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, 2 arc radius linearly increase to 0.51mm by 0.43mm.
Concrete, as preferably, the hand-tight position 4 from the end 3 of described internal thread to described internal thread, 2 arc radius at the bottom of the tooth of described internal thread are 0.43mm; Power-tight position 5 from the hand-tight position 4 of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, 2 arc radius linearly increase to 0.51mm by 0.43mm; Middle part 6 from the power-tight position 5 of described internal thread to described internal thread, 2 arc radius at the bottom of the tooth of described internal thread are 0.51mm.
Wherein, 2 arc radius variation tendencies at the bottom of the tooth of internal thread are contrary with tooth top 1 arc radius variation tendency, be more than 2 arc radius change programmes at the bottom of two kinds of preferred teeth, certainly, those skilled in the art are known, also can there is other change programme, if the end 3 from internal thread is to hand-tight position 4, at the bottom of tooth, 2 arc radius linearly increase to 0.51mm by 0.43mm, or, from the end 3 of internal thread to power-tight position 5, at the bottom of tooth, 2 arc radius linearly increase to 0.51mm etc. by 0.43mm, as long as make 2 arc radius at the bottom of the tooth of internal thread have the change of increase, thus the overall gap existed after making internal and external threads engage reduces.
In the embodiment of the present invention, when improving the box cupling of the preparation embodiment of the present invention by API threaded collar joint, detailed process is as follows:
1. using numerically controlled lathe first to process 2 arc radius at the bottom of all threads of box cupling is 0.51mm, and all screw thread tooth top 1 arc radius are 0.43mm;
2., from box cupling end 3 to middle part 6, screw thread tooth top 1 arc radius can by the following two kinds mode process variations: a. from box cupling end 3 to middle part 6, and tooth top 1 arc radius is linearly reduced to 0.43mm by 0.51mm; B. from box cupling end 3 to hand-tight position 4, tooth top 1 arc radius is 0.51mm, and from hand-tight position 4 to power-tight position 5, tooth top 1 arc radius is linearly reduced to 0.43mm by 0.51mm; From power-tight position 5 to middle part 6, tooth top 1 arc radius is 0.43mm;
3., from box cupling end 3 to middle part 6,2 arc radius at the bottom of thread can by the following two kinds mode process variations: a. from box cupling end 3 to middle part 6, and at the bottom of tooth, 2 arc radius linearly increase to 0.51mm by 0.43mm; B. from box cupling end 3 to hand-tight position 4,2 arc radius at the bottom of tooth are 0.43mm, and from hand-tight position 4 to power-tight position 5, at the bottom of tooth, 2 arc radius linearly increase to 0.51mm by 0.43mm; From power-tight position 5 to middle part 6,2 arc radius at the bottom of tooth are 0.51mm;
4. other size of screw thread is identical with API round thread.
The box cupling of the obtained embodiment of the present invention is improved by API threaded collar joint, water-stop ability after this box cupling coordinates with API Round threaded casing external screw thread is increased dramatically, simultaneously, due within the scope of change from hand-tight position 4 to power-tight position 5 box cupling tooth at the bottom of 2 and the sealed increscence amount of tooth top 1 all linearly increase, the torque resistant ability after internal and external threads coordinates also significantly improves.The present invention processes simple and convenient, compared with API round thread, is with a wide range of applications.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (5)
1. a box cupling, for coal-bed gas exploitation, internal thread is provided with in described box cupling, it is characterized in that, the pitch size of described internal thread is identical, from the end of described box cupling to middle part, the tooth top arc radius of described internal thread has the change diminished, and has become large change from the end of described box cupling to arc radius at the bottom of the tooth of the described internal thread in middle part, and at the bottom of described tooth top arc radius and described tooth, arc radius is all in the scope of 0.43mm-0.51mm.
2. box cupling according to claim 1, is characterized in that, the middle part from the end of described internal thread to described internal thread, and the tooth top arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm.
3. box cupling according to claim 1, is characterized in that, the hand-tight position from the end of described internal thread to described internal thread, and the tooth top arc radius of described internal thread is 0.51mm; Power-tight position from the hand-tight position of described internal thread to described internal thread, the tooth top arc radius of described internal thread is linearly reduced to 0.43mm by 0.51mm; Middle part from the power-tight position of described internal thread to described internal thread, the tooth top arc radius of described internal thread is 0.43mm.
4. the box cupling according to claim 1-3 any one claim, is characterized in that, the middle part from the end of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, arc radius linearly increases to 0.51mm by 0.43mm.
5. the box cupling according to claim 1-3 any one claim, is characterized in that, the hand-tight position from the end of described internal thread to described internal thread, and arc radius at the bottom of the tooth of described internal thread is 0.43mm; Power-tight position from the hand-tight position of described internal thread to described internal thread, at the bottom of the tooth of described internal thread, arc radius linearly increases to 0.51mm by 0.43mm; Middle part from the power-tight position of described internal thread to described internal thread, arc radius at the bottom of the tooth of described internal thread is 0.51mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310017792.9A CN103075114B (en) | 2013-01-17 | 2013-01-17 | A kind of box cupling |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310017792.9A CN103075114B (en) | 2013-01-17 | 2013-01-17 | A kind of box cupling |
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| Publication Number | Publication Date |
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| CN103075114A CN103075114A (en) | 2013-05-01 |
| CN103075114B true CN103075114B (en) | 2016-03-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201310017792.9A Active CN103075114B (en) | 2013-01-17 | 2013-01-17 | A kind of box cupling |
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Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106481286A (en) * | 2016-11-28 | 2017-03-08 | 无锡金顶石油管材配件制造有限公司 | A kind of change screw thread tubing coupling |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0139565A1 (en) * | 1983-09-26 | 1985-05-02 | Vetco Gray Inc. | Conical thread configuration for rapid make-up connection |
| CN101184903A (en) * | 2005-03-02 | 2008-05-21 | 瓦卢雷克曼内斯曼石油及天然气法国公司 | Drill stem connection |
| CN102587842A (en) * | 2012-03-27 | 2012-07-18 | 无锡西姆莱斯石油专用管制造有限公司 | Special round thread highly-torque-resistant pipe coupling |
| CN202483470U (en) * | 2012-02-21 | 2012-10-10 | 无锡西姆莱斯石油专用管制造有限公司 | Special-round-thread joint for oil casing pipes |
-
2013
- 2013-01-17 CN CN201310017792.9A patent/CN103075114B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0139565A1 (en) * | 1983-09-26 | 1985-05-02 | Vetco Gray Inc. | Conical thread configuration for rapid make-up connection |
| CN101184903A (en) * | 2005-03-02 | 2008-05-21 | 瓦卢雷克曼内斯曼石油及天然气法国公司 | Drill stem connection |
| CN202483470U (en) * | 2012-02-21 | 2012-10-10 | 无锡西姆莱斯石油专用管制造有限公司 | Special-round-thread joint for oil casing pipes |
| CN102587842A (en) * | 2012-03-27 | 2012-07-18 | 无锡西姆莱斯石油专用管制造有限公司 | Special round thread highly-torque-resistant pipe coupling |
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| CN103075114A (en) | 2013-05-01 |
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